SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3daf6c833ec79ada92f6dea6d44b082e17c841d0d35d0ac48d4e820362bdb770' 
  AND token = 'GDBoljhsq29WnlA/YnCYTAZypkhwQwRUFb7+82fLfAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}